*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19864
19870
19880
19892
19901
19910
19921
19934
19940
19953
19960
19974
19980
19990
20000
20010
20023
20030
20040
20050
20062
20070
20084
20091
20102
20112
20120
20130
20140
20150
20160
20170
Total33